Indicating fuse plug



Oct. 9, 1928.

J. F. QRLANDO INDI CATING FUSE PLUG Filed May 1926 Patented Oct. 9,1-928.

UNITED STATES PATENT OFFICE.

JOSEPH FRANCIS ORLANDO, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR OFONE-HALF TO ROBERT GLORIOSO, OF WASHINGTON, DISTRICT OF COLUMBIA.

INDIGATING FUSE PLUG.

Application filed May 1, 1926. Serial No. 106,157.

This invention relates in general to fuse plugs and more particularly toa type of fuse plug comprising means for indicating the condition of thefusible element.

Heretofore in fuse plugs of this character there have been certainfundamental disadvantages which this invention seeks to overcome. It isa well known fact that when the fusible element of such plugs melts dueto the passage of an excess current, there is caused a discoloration ofthe transparent material, generally mica, embodied in the top or cap ofthe fuse, thereby obstructing the vision of the fusible element. tor hasproved a particularly objectionable feature in that this discolorationis oftimes indistinguishable from the natural discoloration orimpurities frequently found in such mica. Further, fuse plugs of thischaracter have previous to this time, been of essentially difierentconstruction from the ordinary type, hence the manufacture of thesefuses has necessitated a radical change in the present design andconstruction.

t is an object of this invention to provide a fuse plug embodying anindicating means whereby it may be readily ascertained whether or notthe fusible element is defective.

Another object of this invention is to provide a fuse plug embodying anindicating means having the indicating means and the transparentmaterial of the cap protected from the effects of discoloration causedby the melting of the fusible element.

A further object of this invention is to provide a fuse plug embodyingan indicating means having the indicating means so constructed as to beessentially applicable to the ordinary type of fuse plug, thusprecluding the need of changing the design of fuse plugs for adaptationof this invention.

With these and other objects in view which may be incident to myimprovements, the invention consists in the parts and combinations to behereinafter set forth and claimed, with the understanding that theseveral necessary elements comprising my invention, may be varied inconstruction, proportions and arrangement, without departing from thespirit and scope ofthe appended claims.

In order to make my invention more clearly understood, I have shown inthe accom- This facpanying drawings means for carrying the same intopractical effect, without limiting the improvements in their usefulapplications to the particular constructions, which for the purpose ofexplanation have been made the subject of illustration.

In the drawings forming a part, of this specification:

Figure l is a side elevation sectional view of a conventional fuse plugshown as em bodying the present invention;

Fig. 2 is a top plan view thereof;-

ig. 3 is a top plan sectional view taken on line 33 of Figure 1;

Fig. dis a perspective view of the component parts of the indicatingdevice.

Referring by numerals to the drawings and more particularly to Figure 1,l is a hollow housing portion of a fuse plug of conventionalconstruction. The wall of the housing. is provided with apertures 2 and3,

the aperture 2 being desired to receive one end of a fusible element lformed-with a restricted portion, in order that there may be provided apoint of high resistance on the fusible element better shown in Figure4. A metal collared bushing 6 iseinbodied in the base of the housing,the inner collar being adapted to act as a securing means for the otherend of the fusible element 4. The outer collar is designed to serve asone terminal of a fuse plug.

It is preferred that this plug body be com osed of one of the numerousphenol 0011C ensation products although it may be of the usual porcelainconstruction.

A portion of the outer wall of the housing is threaded thereby beingadapted to receive a threaded metallic sleeve 5 to act as a securingmeans for the plug and as the other contact thereof having contact withthe other end of the fusible element 4 projecting through the aperture2.

To the top of the housing 1 is secured in the usual manner a cap 7provided with a rectangular aperture 8 and interposed therebetween, adisk of transparent material 9.

0n the fusible element 4 at the point of the greatest resistance issecured a member 10 forming one of the novel elements of this invention,comprising a clamp portion 11 and a cylindrical channeled member 12 morefully shown in Figure 4. The clamped portion 11 is adapted to be clampedon the fusible element at the point of the greatest resistance. Aflexible strip member 13 having designations thereon in respect to thecondition of the fusible element is secured by the channeled portion 12of the member 10.

The flexible stripmember 13 referably composed of any suitable ruggedabric tape and impregnated with any non-inflammable substance isdesigned to be supported by an elongated plate member 14 interposedbetween the disk of transparent material 9 and the top of the housingpermitting free operation of the strip member and secured thereon by thecap 7. v The elongated plate member 14 is provided with an aperture 15near one longitudinal edge thereof and disposed adjacently thereto andaligned therewith on the opposite edge, a recess 16. The aperture andthe recess are preferably formed by cutting the plate and bending theout portions downward in' arcuate formation better illustrated in Figure4. The flexible tape member 13 is adapted-to pass through the aperture15 across the top of the plate over the recess'16, and having theopposite end held in the aper ture 3 provided in the wall of the housing1 and oppositely disposed to the aperture 2.

In Figure 3 is shown a top plan view of the plate member 14 rested onthe'top of the housingl and secured thereon by the cap 7. The tape 13having one end secured to the fusible element 4, the other to the spiralspring 20 and passing through theaperture 15 and over the recess 16.

The mode of operation of the device may be readily understood havingreference to Figures 1 and 3. ment melts, it will necessarily separateat the point of the greatest resistance thereby releasing the member 10.The tape portion 13 held in tension by the spring 20 will be drawnthrough the aperture 15 and over the recess 16 by the force of thespring. The channeled portion 12 of the member 10 will act as a stopmeans for the tape when it reaches the aperture 15. It may be seen thatthe indications will thus change to denote the condition of the fusibleelement.

There is accomplished by this invention an improved indicating deviceadaptable to' fuse plugs of conventional construction,

whereby the condition of the fusible element may readily be ascertained.Further thereis embod ed in said device the provision of a meanstoprotect the indicating elements from discoloration resultant from thefusation of the fusible element.

While I have shown and described the preferred embodiment of myinvention, I wish it to be understood that I do not confine myself tothe precise details of construction herein set forth, by way ofillustratiomasfit is apparent that many changes and variations may bemade therein, by those skilled When the fusible element, means toindicate the conditionof the fusible element comprising an indicatingmember having a supporting means secured to the fusible element at thepoint of the greatest resistance and means to operate the indicatingmember vertically and horizontally comprlsing a spiral spring.

3. In a fuse plug comprising a housing of a phenol condensation productand embodying a fusible element, means to indicate the condition of thefusible element comprising an indicating member having a supportingmeans secured to the fusible element at the point of the greatestresistance and means to operate the indicating member vertically andhorizontally comprising a spiral sprlng.

4. In a fuse plug embodying a housing, a 5

fusible element and a transparent cap, means to protect the transparentcap from discoloration comprising a plate member interposed between thefusible element and the cap. i

5. In a fuse plug embodying a housing, a fusible element and atransparent cap, the combination of a means to protect the transparentcap from discoloration and a means to indcate the condition of thefusible element comprisin a plate member interposed between the fuel leelement and the cap, the plate being adapted to support the indicatingelement. V I

6. In a fuse plug embodying a housing, a fusible element and atransparent cap, the combination of. a means to protect the transparentcap from discoloration and a means to indicate the condition of thefusible element comprising a plate member interposed between the fusibleelement and the cap, an indicating means secured to the fusibleelementand supported by the plate member.

7. In a fuse plug embodying a housing, a fusible element and atransparent cap, the .120 combination of a means to protect thtransparent cap from discoloration and a means to indicate the conditionof the fusible ele. ment comprising a plate member having an/ apertureinterposed between the fusible element and the cap, an indicating meanssecured to the fusible element and designed to pass through the aperturePIOVlded in the plate member.

8. In a fuse plug embodying a housing, a 13 aperture provided in theplate member.

fusible element and a transparent cap,

9. In a fuse plug embodying a housing, a the combination of a means toprotect the transparent cap from dscoloration and a means to indicatethe condition of the fusible element comprising an elongated platemember having an aperture and a notch adjacently disposed and inlongitudinal alignment therewith secured to the plug housing by the capmember and an indicating device comprising a tape member having one endsecured to the fusible element, adapted to pass through the notch andaperture pro vided in the plate member and having the opposite endresiliently secured.

10. In a fuse plug embodying a housing, a fusible element and atransparent cap, the combination of a means to protect the transparentcap from discoloration and a means to indicate the condition of thefusible element comprising an indicating device comprising a tape memberhaving one end secured to the fusible element at the point of leastresistance, adapted to pass through the notch and an aperture providedin the plate member and having the opposite end attached to a springmember secured to the housing of the plug.

11. In a fuse plug embodying a housing, a fusible element and atransparent cap, the

combination of a means to protect the transparent cap from discolorationand a means to indicate the condition of the fusible element comprisingan indicating device comprising a tape having thereon desiredinclicators, having one end provided with a stop member secured to thefusible element the point of greatest resistance, adapted to passthrough the aperture and notch provided in the plate member and havingthe opposite end attached to a spiral spring member secured to thehousing of the plug.

12. In a fuse plug embodying a housing, a fusible element and atransparent cap, the combination of a means to protect the trans parentcap from discoloration and a means to indicate the condition of thefusible ele ment protected from discoloration, comprising an indIcatingdevice comprising a tape having thereon desired indicators having oneend provided with a stop member secured to the fusible element at thepoint of greatest resistance, adapted to pass through the aperture andnotch provided in the plate member and having the opposite end attachedto a spiral spring member secured to the housing of the plug.

13. In a fuse plug a fusible element, a flexible strip including a sign,a plate member supporting the flexible strip and means for moving theflexible strip with reference to the plate member to indicate thecondition of the fusible element.

14. In a fuse plug embodying a housing, a fusible element and atransparent cap, means to protect the transparent cap, fromdiscoloration comprising a plate member and a flexible strip interposedbetween the plate member and the cap.

In testimony whereof I afiix my signature.

JOSEPH FRANCIS ORLANDO.

